The subject matter disclosed herein relates to optical storage, and more particularly, to techniques for decoding data in optical storage systems.
As computing power has advanced, computing technology has entered new application areas, such as consumer video, data archiving, document storage, imaging, and movie production, among others. These applications have provided a continuing push to develop data storage techniques that have increased storage capacity and increased data rates.
One example of the developments in data storage technologies may be the progressively higher storage capacities for optical storage systems. For example, the compact disk, developed in the early 1980s, has a capacity of around 650-700 MB of data, or around 74-80 min. of a two channel audio program. In comparison, the digital versatile disk (DVD) format, developed in the early 1990s, has a capacity of around 4.7 GB (single layer) or 8.5 GB (dual layer). Furthermore, even higher capacity storage techniques have been developed to meet higher demands, such as the demand for higher resolution video formats. For example, high-capacity recording formats such as the Blu-ray Disc™ format is capable of holding about 25 GB in a single-layer disk, or 50 GB in a dual-layer disk. As computing technologies continue to develop, storage media with even higher capacities may be desired. For example, holographic storage systems and micro-holographic storage systems are examples of other developing storage technologies that may achieve increased capacity requirements in the storage industry.
Along with increases in data capacity, high data rates are also desired. For example, the video bit rate for a standard DVD format may be about 9.8 Mbps, and the video bit rate for a standard Blu-ray Disc™ format may be about 40.0 Mbps. Further data rate increases may also be expected as higher capacity storage systems are developed. To support such high rates of data processing, a high amount of energy may be used for the numerous calculations and steps involved in typical channel decoding procedures. For example, an efficient Reed-Solomon decoder may operate at 1 Gbps and may consume approximately 200 mW/s. Complex soft-decision decoding may consume significantly more power.
Complex decoding processes used in optical storage systems may utilize a significant amount of energy and result in an accumulation of heat, which may result in a need for internal and/or external cooling. Such cooling methods may be undesirable due to unacceptable long-term failure rates. Thus, efficient data decoding processes may be desirable.